A prospective multicenter phase II study of oral and i.v. vinorelbine plus trastuzumab as first-line therapy in HER2-overexpressing metastatic breast cancer.

BACKGROUND: To evaluate the efficacy and safety of oral and i.v. vinorelbine plus trastuzumab as first-line regimen in a patient-convenient application for human epidermal growth factor receptor 2 (HER2)-overexpressing patients with metastatic breast cancer. PATIENTS AND METHODS: Forty-two women were enrolled in a multicenter study. The patients received i.v. vinorelbine at a dose of 25 mg/m(2) on day 1 followed by oral vinorelbine at a dose of 60 mg/m(2) on days 8 and 15 in a 3-week cycle. Standard dose trastuzumab was given at 3-week intervals.
RESULTS: Complete response was observed in 7 patients (18.9%) and partial response in 19 patients (51.4%), for an overall response rate of 70.3% [95% confidence interval (CI) 53.0-84.1]. The disease control rate reached 91.9% (95% CI 78.1-98.3). The median time to progression was 9.3 months, while median overall survival reached 35.6 months. Hematological and non-hematological toxic effects were acceptable with grade 3-4 leukopenia of 14% and neutropenia of 38%; cardiac toxicity did not reach the level of clinical relevance.
CONCLUSION: The combination of i.v. and oral vinorelbine plus trastuzumab demonstrates high activity and good tolerability in first-line treatment of HER2-overexpressing metastatic breast cancer. In addition, it offers convenience for the patients with only one i.v. treatment every 3 weeks.